diff --git a/bin/pt-kill b/bin/pt-kill
index 29584395..f725a67e 100755
--- a/bin/pt-kill
+++ b/bin/pt-kill
@@ -2959,7 +2959,7 @@ sub parse_event {
                   int($query_start),        # START
                   $etime,                   # ETIME
                   $time,                    # FSEEN
-                  { $curr->[STATE] => 0 },  # PROFILE
+                  { ($curr->[STATE] || "") => 0 }, # PROFILE
                ];
             }
          }
@@ -2973,7 +2973,7 @@ sub parse_event {
                int($query_start),        # START
                $etime,                   # ETIME
                $time,                    # FSEEN
-               { $curr->[STATE] => 0 },  # PROFILE
+               { ($curr->[STATE] || "") => 0 }, # PROFILE
             ];
          }
       }
diff --git a/bin/pt-query-digest b/bin/pt-query-digest
index e4dc5cb9..15155889 100755
--- a/bin/pt-query-digest
+++ b/bin/pt-query-digest
@@ -2398,7 +2398,7 @@ sub parse_event {
                   int($query_start),        # START
                   $etime,                   # ETIME
                   $time,                    # FSEEN
-                  { $curr->[STATE] => 0 },  # PROFILE
+                  { ($curr->[STATE] || "") => 0 }, # PROFILE
                ];
             }
          }
@@ -2412,7 +2412,7 @@ sub parse_event {
                int($query_start),        # START
                $etime,                   # ETIME
                $time,                    # FSEEN
-               { $curr->[STATE] => 0 },  # PROFILE
+               { ($curr->[STATE] || "") => 0 }, # PROFILE
             ];
          }
       }
diff --git a/lib/Processlist.pm b/lib/Processlist.pm
index 29128fb7..556c1832 100644
--- a/lib/Processlist.pm
+++ b/lib/Processlist.pm
@@ -279,7 +279,7 @@ sub parse_event {
                   int($query_start),        # START
                   $etime,                   # ETIME
                   $time,                    # FSEEN
-                  { $curr->[STATE] => 0 },  # PROFILE
+                  { ($curr->[STATE] || "") => 0 }, # PROFILE
                ];
             }
          }
@@ -294,7 +294,7 @@ sub parse_event {
                int($query_start),        # START
                $etime,                   # ETIME
                $time,                    # FSEEN
-               { $curr->[STATE] => 0 },  # PROFILE
+               { ($curr->[STATE] || "") => 0 }, # PROFILE
             ];
          }
       }
diff --git a/t/lib/Processlist.t b/t/lib/Processlist.t
index a44c2984..0bab3347 100644
--- a/t/lib/Processlist.t
+++ b/t/lib/Processlist.t
@@ -9,7 +9,7 @@ BEGIN {
 use strict;
 use warnings FATAL => 'all';
 use English qw(-no_match_vars);
-use Test::More tests => 35;
+use Test::More;
 
 use Processlist;
 use PerconaTest;
@@ -862,7 +862,35 @@ eval { $pl->find([$proc], %find_spec) };
 ok !$@,
  "Bug 923896: NULL Time in processlist doesn't fail for idle_time+Command=Sleep";
 
+# #############################################################################
+# NULL STATE doesn't generate warnings
+# https://bugs.launchpad.net/percona-toolkit/+bug/821703
+# #############################################################################
+
+$procs = [
+   [ [1, 'unauthenticated user', 'localhost', undef, 'Connect', 7,
+    'some state', 1] ],
+   [ [1, 'unauthenticated user', 'localhost', undef, 'Connect', 8,
+    undef, 2] ],
+],
+
+eval {
+   parse_n_times(
+      2,
+      code  => sub {
+         return shift @$procs;
+      },
+      time  => Transformers::unix_timestamp('2001-01-01 00:05:00'),
+   );
+};
+
+is(
+   $EVAL_ERROR,
+   '',
+   "NULL STATE shouldn't cause warnings"
+);
+
 # #############################################################################
 # Done.
 # #############################################################################
-exit;
+done_testing;